Lubricant compositions containing phosphoramidate derivatives

ABSTRACT

1. A LUBRICANT COMPOSITION CONSISTING OF ESSENTIALLY OF A MAJOR AMOUNT OF LUBRICATING OIL AND A MINOR AMOUNT, FROM 0.01% TO ABOUT 3% BY WEIGHT, OF A COMPOUND HAVING THE FORMULA   2-(2-(Y=),5-R1,5-R2-1,3,2-DIOXAPHOSPHORINAN-2-YL-),3-   (H2N-),5-R3-1,2,4-TRIAZOLINE   WHEREIN R1 AND R2 ARE EACH SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND C1-20 ALKYL GROUPS, R3 IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, ALKYL, ARYL AND ALKARYL, SAID (HYDROCARBYL) ALKYL, ARYL AND ALKARYL GROUPS HAVING FROM 1 TO 12 CARBON ATOMS, AND Y IS SELECTED FROM THE GROUP CONSISTING OF OXYGEN AND SULFUR.

United States Patent 3,846,317 LUBRICANT COMPOSITIONS CONTAINING PHOSPHORAMIDATE DERIVATIVES Vincent G. Lintzenich, Collinsville, Ill., assignor to Shell Oil Company No Drawing. Continuation-impart of application Ser. No. 115,868, Feb. 16, 1971, which is a continuation-in-part of application Ser. No. 803,078, Feb. 27, 1969, and a continuation-in-part of application Ser. No. 200,217, Nov. 18, 1971, which is a continuation-in-part of application Ser. No. 66,606, Aug. 24, 1970, ,all now abandoned. This application May 9, 1972, Ser. No. 251,624

Int. Cl. Cm 1/46, 1/48 US. Cl. 252-46.7 8 Claims ABSTRACT OF THE DISCLOSURE Phosphoramidates of triazoles, such as 1,2,4 triazoles, effective as load-carrying agents, corrosion inhibitors, antioxidants increase the stability of lubricant compositions.

CROSS REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part of applicants copending application Ser. No. 115,868, filed Feb. 16, 1971, now abandoned, said copending application being a continuation-in-part of applicants application Ser. No. 803,078, filed Feb. 27, 1969, now abandoned; and a continuation-inpart of applicants copending application Ser. No. 200,217, filed Nov. 18, 1971, now abandoned, which is a continuation-in-part of applicants application Ser. No. 66,606, filed Aug. 24, 1970, now abondoned, the latter application being a divison of said Ser. No. 803,078.

BACKGROUND OF THE INVENTION Lubricating oils which are employed in high speed engines, particularly in gas-turbine engines, must be able to withstand extreme temperature and pressure variations, must be oxidation resistant, and must also be effective in controlling corrosion which would otherwise be excessive because of the severe operating conditions. Only a select few lubricants are known to the art which possess the properties requisite for use in this application, and since each successive generation of ga-turbine engines is designed to operate at higher temperatures to optimize performance, the number of qualified lubricants is diminishing. Therefore, to keep pace with increasingly more stringent specification requirements, there is a continuing need in the industry for the development of additives which will impart necesary properties to lubricating oils used in high speed engines. This invention relates to such additives and to lubricating compositions containing them.

SUMMARY OF THE INVENTION It has now been found that a novel class of phosphorus containing triazole derivatives, i.e., phosphorinane-aminotriazole derivatives, impart not only good load-carrying characteristics to lubricant compositions, but also are effective in inhibiting corrosion and improving the antioxidant properties and stability of the oil. This class of novel compounds can be represented by the general formula wherein R and R are H or alkyl, X is a heterocyclic group containing two or more nitrogen atoms in which 3,846,317 Patented Nov. 5, 1974 the phosphorus atom is attached to a ring nitrogen adjacent to another ring nitrogen, and Y is selected from the group consisting of oxygen and sulfur.

The invention therefore relates to a novel class of additives and to lubricant compositions containing such compounds. More particularly it relates to phosphorinaneamino-triazole derivatives which are effective in improving the load-carrying capacity and the anticorrosion, antioxidant, and stability characteristics of mineral and synthetic lubricating oils. These preferred derivatives may be represented by the following formula wherein R and R are each selected from the group consisting of hydrogen and C alkyl groups, R is selected from the group consisting of hydrogen, alkyl, aryl and alkaryl, said hydrocarbyl groups having from 1 to 12 carbon atoms, and Y is selected from the group consisting of oxygen and sulfur. A more preferred class of compounds are those in which R, and R are alike or different C alkyl groups. Especially preferred are compounds wherein R is hydrogen and R and R are alike or different C alkyl groups. However, the compounds in which R and R are methyl and R is hydrogen have been found to be especially advantageous in the composiitons of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Generally any heterocyclic compound such as substituted or unsubstituted imidazoles, pyrazoles, triazoles and the like which contain an amino group substituted on the heterocyclic ring can be reacted with a 1,3-dioxa-2-oxo-2- chlorophosphorinane to form the compounds of the invention. Amino triazoles are a preferred class of reactants of this type, especially triazoles having nitrogen atoms in the 1,2,4 positions. Thus a highly suitable class of compounds are those in which X is a 1,2,4-triazole and R and R are alkyl groups.

The novel compounds of the invention may be conveniently prepared by reacting equimolar quantities of an alkyl substituted 1,3-dioxa-2-oxo-2-chlorophosphorinane or an alkyl substituted 1,3-dioxa-2-thiono-2-chlorophosphorinane with a substituted or unsubstituted 3-amino-1,2,4- triazole. Preferred substituted triazoles are those substituted in the 5 position. Examples of such triazoles are 3- amino-1,2,4-triazole, 3 amino-S-pentyl-l,2,4-triazole, 3- amino-S-heptyl-l,2,4-triazole, S-amino 5 (4-is0propylphenyl)-l,2,4-triazole, B-amino-S-pyridyl-1,2,4-triazole, 3- amino-4-anilido-1,2,4-triazole, 3 amino-5-methyl-l,2,4- triazole, 3-amino-5-(p-tert-butylphenyl)-1,2,4-triazole, 3- amino-S-phenyl-l,2,4-triazole and the like.

Suitable oxoor thiono-phosphorinanes may be prepared by reacting a 1,3-alkanediol with phosphorus oxychloride or thiophosphoryl chloride in the presence of a hydrogen halide sequestering agent. Examples of suitable 1,3-alkanediols include 1,3-propanediol, 2,2-dimethyl-1,3- propanediol, 2,2 diethyl-l,3-propanediol, 2-butyl-2-ethyl- 1,3-propanediol, 2-butyl-2-methyl-1,3-propanediol, 2,2-dioctyl1,3-propanediol, 2 methyl-Z-octadecyl-1,3-propanediol, 2-octadecyl-1,3-propanediol and the like. Suitable sequestering agents include various pyridines and tertiary amines such as triethylamine.

Further details concerning the method of preparation of these compounds are given in the examples.

The novel additives of this invention may be dissolved or dispersed in either mineral or synthetic lubricating oils in minor amounts of from 0.01% to about 3%, preferably from 0.1 to about 1% by composition weight. These compounds have been found to be extremely useful in synthetic oils which are Often used under severe conditions where the advantages of these additives become more pronounced.

Synthetic lubricants suitable for the invention are of various types, such as aliphatic esters, silicones, polyalkylene oxides, polyphenyl ethers, fluorinated hydrocarbons, polyolefins, and phosphate esters. Examples of silicones include methyl silicone, methylphenyl silicone, methylchlorophenyl silicone, etc. Examples of polyalkylene oxides are polyisopropylene oxide, polyisopropylene oxide diether, and polyisopropylene oxide diester. Fluorinated hydrocarbons include fluorinated oils and perfluorinated hydrocarbons. Preferred synthetic lubricant base stocks are esters of alcohols having 1 to 20, especially 4 to 12, carbon atoms and aliphatic carboxylic acids having from 3 to 20, especially 4 to 12, carbon atoms.

Particularly suitable ester oils are diisooctyl adipate, diisodecyl adipate and mixtures thereof. Other preferred esters for use as base stocks in the present invention are esters of monocarboxylic acids having 3 to 12 carbons and polyalcohols, such as pentaerylthritol, dipentaerythritol, and trimethylolpropane. Pentaerythrityl and dipentaerythirtyl esters of mixtures of C acids are particularly suitable base oils for the compositions of the invention. Preparation of these esters is described in Eichemeyer, US. 3,038,859, issued June 12, 1962, and Young, US. 3,121,109, issued Feb. 11, 1964.

In addition to the aforementioned synthetic oils, the additives of this invention may also be incorporated in mineral lubricating oils. The mineral lubricating oil can be obtained from paraffinic, naphthenic, asphaltic or mixed base crudes and/or mixtures thereof, for example, neutral oils having viscosities of from 100 to 6500 SSU at 100 F.

Other additives can also be incorporated into the lubricating compositions according to the present invention. For example, any of the additives recognized in the art to perform a particular function or functions, i.e., viscosity index improvers such as methacrylic polymers, an tioxidants, such as amines, phosphorus or phenolic compounds, i.e., phenyl-alpha-naphthylamine, dioctyldiphenyl amine; zinc dialkyl dithiophosphate, or 4,4-methylene-bis (2,6-di-t-butylphenol); anti-foam agents, corrosion inhibitors; anti-rust agents and the like can be used.

The following examples are illustrative of the novel compositions of the invention and their manner of preparation and use.

EXAMPLE I Compound A 2- (5-amino-1,2A-triazol-1-yl) -5,5-dimethyl- 2-ox0-1,3,2-dioxaphosphorinane The above-identified compound was prepared by reacting equimolar quantities of 3-amino-1,2,4-triazole and 1,3-dioxa-5,5-dimethyl-2-oxo-2-chloro phosphorinane in toluene by refluxing the mixture at 100 to 110 C. at atmospheric pressure in the presence of a tertiary amine sequestering agent.

The chloro-phosphorinane reactant was prepared by slowly adding 306 g. (2.0 moles) of phosphorus oxychloride to 104 g. (1.0 moles) of 2,2-dimethyl-1,3-propanediol in 250 ml. of benzene with stirring. The stirring Was continued for two hours after which the solvent was removed by letting the reaction mixture stand overnight in vacuo.

The foregoing reactions are represented by the following equations:

2-(5-amino-1,2,4-triazo1-1-yl)-5,5-dimethyl- 2-thiono-1,3,2-dioxaph0sphorinane This compound was synthesized according to the procedure outlined for preparing Compound A, except that thiophosphoryl chloride was used in place of phosphorus oxychloride to prepare the chloro-phosphorinane reactant. Analysis.-Calcd for C H PN O S: P, 12.5; N, 22.6; S, 12.9. Found: P, 12.8; N, 22.4; S, 12.6; m.p. 177 C.

Compound C HsCz C-O N=CH 2- (5amino-1,2,4-triazol-1yl) -5,5-diethyl- 20xo1,3,2-clioxaphosph0rinane This compound was prepared according to the procedure outlined for preparing Compound A, except that 2,2-diethyl-1,3-propanediol was used in place of 2,2-dimethy1-1-3-propanediol.

September 1952. Test results are shown in Table 1.

for use in the compositions of the invention are:

Compound F PN I i 2- (5-arnino-3-pheny1-1,2,4-triazo1-1-yl) -5-ethyl-5-buty1- 2-oxo-1,3,2 dioxaph0sphorinane 2-[5-amino-3-(-isopropylphenyD-l,2,4 triazol-l-yll- 5,5-dioctyl-2-thion0-1,3,2-dioxaphosphonnane 2-(5-amino-3-heptyl-1,2,4-triazol-1-yl)- 5,5-dimethyl-2-oxo-1,3,2-dioxaphosphormane Compound I C N=JIH 2-(5-amino-1,2,4-triazol-1-yl)-5-ethyl- 5-butyl-2-thiono-l,3,2-dioxaphosphormane EXAMPLE II p of aircraft-quality gears to which a load is applied while the machine is in motion. Results are reported in terms of pounds per inch of tooth width. A complete description of this test is given in ASTM Bulletin No. 184, p. 41,

TABLE I Ryder Gear Test Composition: Average rating (lbs./ in.) Oil X 2,500 Composition 2 (Oil X plus 0.2% w. Compound A) 3,265 Composition 2 (Oil X plus 0.2% w. Compound B) 3,260 Oil Y 1,700 Composition 3 (Oil Y plus 0.2% W. Compound A) 2,815 Composition 4 (Oil X plus 0.2% w. Compound D) 3,070

11 Oil XEsters of monoand dipentaerythritol plus 2.0% w. p,p-di-t-octyldiphenylamine, and 1.0% w. phenyl-alphanaghthylamine.

Oil YDiis0octyl and diisodecyl adipates, plus 2% W. p,p-di-t-octyldiphenylamine, 0.5% w. N-benzyl-3,7-dioctylphenothiazine, 1.0% w. vinylpyrrolidone-methacrylate copolymer, and 0.1% w. quinizarin.

EXAMPLE III In order to determine the antioxidation and anticorro sion properties of the compositions of Example II, a series of corrosion and oxidation stability tests were run in accordance with military specification MIL-L-23699A. Results of these tests are presented in Table II and III.

TABLE II Corrosion and oxidation stability, 400 F., 72 hours MIL-L- 23699A specifi- Corrosion, mgJcmfl cation limits, Composi- Composimax. Oil X tion 1 tion 2 Magnesium- =!;0. 2 -2. 53 +0. 03 +0. 01 i0. 4 1. 89 -0. 09 0. l2 :i:0. 2 0.01 -0. 01 0. 01 5:0. 2 0. 01 -0. 01 0.00 :bO. 2 0. 05 -0. 02 -0. 09

TABLE III Corrosion and oxidation stability,

F., 72 hours Corrosion and 425 F., 48 hours MIL-L- 23699A Corrosion, mgJcm. specification Composi- Composilimits, Compsition 1 tion 2 max. tion 3 -0. 02 -0. 02 =|=0. 2 +0. 01 --0. 17 0. 21 if]. 4 0. 02 -0. 02 -0. 01 i0. 2 0. 01 0. 00 +0. 01 :i:0. 2 0. 00 0. 02 -0. 05 5:0. 2 -0. 05

EXAMPLE IV A further indication of the stability of the compositions of the invention was obtained by subjecting samples of Compositions 1 and 2 to the Alco High Temperature Deposition Test. Basically this test involves circulation of aerated oil over a heated deposition tube. The temperature of the tube is controlled at 525 F. on the inlet side and reaches 650 to 700 F. at the outlet end of the tube. The temperature profile of the tube is measured at the start and shortly before the end of the test. These temperature profiles and the tube deposits per unit length are used to determine the performance of the oil. The critical temperature is that temperature at which deposits begin to significantly affect the heat transfer characteristics of the oil. A temperature of above 600 F. is considered to be very satisfactory. The overall deposit rating is obtained from a combination of the visual deposit rating of the tube, the tube deposit Weight and the filter deposit weight. An overall rating of less than 50 is considered very good, a rating of below 15 is considered exceptional. A detailed description of this test is given in Proceedings of the USAF-Southwest Research Institute Turbine Lubrication 7 Conference, Sept. 13-15, 1966, Southwest Research Institute, San Antonio, Texas, pg. 152. Test results are shown in Table IV.

TABLE IV.ALCOR HlGHT'llglsi li dPERATURE DEPOSITION Composition 2 Critical temperature, F 650 640 Tube deposits, mg 4. 8 14. 6

Overall rating 8. 5 l2. 5

EXAMPLE V To further illustrate the load-carrying or extreme pressure (EP) capabilities of the additives of the invention the following compositions identified as Compositions 5 through 8 were formulated as in Table V and subjected to the Shell Four-Ball Wear Test. Test results are shown in Table VI.

TABLE V Composition 5 6 7 8 Component, percent wt.:

Oil Z, HVI 100N (viscosity a)pproxib According to the invention.

The Shell Four-Ball Wear Test is widely accepted as a repeatable screening test for lubricants having EP properties. Scar diameters less than 0.42 mm. indicate that a lubricant has satisfactory EP characteristics and will probably perform adequately. Thus the performance of the compositions according to the invention demonstrate that such compositions possess EP properties to a high degree.

EXAMPLE VI To particularly test the corrosivity of the inventive compositions with respect to lead, a lead corrosion test (described below) was conducted. Test results are as shown in Table VII.

The Lead Corosion (LC) Test consists of the addition of cleaned and weighed lead coils to a sample of oil, which is then placed in the Micro Air Oxidation Test (MAOT) apparatus at 325 F. The MAOT is ordinarily used to measure the oxidation stability of oils. A vessel containing 20g of sample is placed in a constant temperature bath. The vessel is fitted with a condenser and a fritted bubbler tube. Clean dry air is bubbled through the oil at a constant flow rate of 30 ml./min. After passage through the oil sample, the air stream is directed through a Beckman oxygen analyzer. This device senses the amount of oxygen present in the air stream, thereby providing a measure of the oxygen absorbed by the oil sample. The use of the MAOT apparatus makes it possible to examine simultaneously the oxidation stability and corrosivity of the oil. After five hours, the wire coils are removed, washed with benzene and methanol, wiped free of deposits and weighed. The data appear to be reproducible within :2 mg.

TABLE VII Lead Corrosion Tes Composition: Weight loss, mg. Composition 5 -5.8 Composition o 2.6

a See Table V.

b According to the invention.

The results clearly demonstrate the resistance of the instant compositions to lead corrosion.

The foregoing test results clearly establish that phosphorinane-triazole derivatives are extremely suitable lubricating oil additives. The data presented in Table I and Table VI indicate that the addition of small amounts of the phosphorus containing triazoles improves the loadcarrying capacity of the base oil by over 760 lbs/in. in Composition 1 and 2, 1115 lbs/in. in Composition 3 and 570 lbs./ in. in Composition 4. In addition these additives are also excellent corrosion inhibitors and antioxidants as evidenced by the test results presented in Tables II, III and VII. Compositions l and 2 are shown to easily meet the very restrictive corrosionrequirements of military specification MIL-L-23 699A. The exceptional performance of these compositions in the Alcor High Temperature Deposition Test as shown in Table IV, is indicative of their inherent stability in a severe environment. Additionally, the performance of Compositions 6 and 8 in the Four Ball Test and Composition 6 in the LC Test demonstrates the load-carrying and anticorrosion characteristics of these compositions in mineral oils.

The phosphorinane-triazole containing compositions of the invention therefore represent a class. of lubricants which not only possess an excellent load-carrying capacity, but also have excellent anti-corrosion and oxida tion properties and good high temperature stability.

Other disclosed compositions give equivalent, although not identical, results.

I claim as my invention:

1. A lubricant composition consisting essentially of a major amount of lubricating oil and a minor amount, from 0.01% to about 3% by weight, of a compound having the formula wherein R and R are each selected from the group consisting of hydrogen and C alkyl groups, R is selected from the group consisting of hydrogen, alkyl, aryl and alkaryl, said [hydrocarbyl] alkyl, aryl and alkaryl groups having from 1 to 12 carbon atoms, and Y is selected from the group consisting of oxygen and sulfur.

2. The composition of claim 1 wherein R and R are C alkyl groups.

3. The composition of claim 2 wherein R is hydrogen and R and R are C alkyl groups.

4. The composition of claim 3 wherein the lubricating oil is a mineral lubricating oil.

5. The composition of claim 3 wherein the lubricating oil is a synthetic lubricating oil.

6. The composition of claim 3 wherein R and R are methyl groups.

9 10 7. The composition of claim 6 wherein Y is oxygen. 3,227,727 1/ 1966 Greenley et a1. 25249.9 XR 8. The composition of claim 6 wherein Y is sulfur. 3,711,404 1/1973 Redmore 25249.9 XR 3,623,985 11/1971 Hendrickson 25246.7 XR References Cited 2,875,235 2/1959 Lanham 25246.7 XR CL 2,892,862 6/1959 Lanham 25246.7 XR

3,192,162 6/1965 Bartlett et a1. 25246.7 XR 389; 260296 308 R, 309, 310 R 

1. A LUBRICANT COMPOSITION CONSISTING OF ESSENTIALLY OF A MAJOR AMOUNT OF LUBRICATING OIL AND A MINOR AMOUNT, FROM 0.01% TO ABOUT 3% BY WEIGHT, OF A COMPOUND HAVING THE FORMULA 